Lymph Node Evaluation in Robot-Assisted Versus Video-Assisted Thoracoscopic Esophagectomy for Esophageal Squamous Cell Carcinoma: A Propensity-Matched Analysis

Caseload per Year in Robotic-Assisted Minimally Invasive Esophagectomy: A Narrative Review

Esophageal surgery is deemed one of the most complex visceral operations. There is a well-documented correlation between higher caseload and better outcomes, with hospitals that perform more surgeries experiencing significantly lower mortality rates. The approach to caseload per year varies across different countries within Europe. Germany increased the minimum annual required caseload of complex esophageal surgeries from 10 to 26 starting in 2023. Furthermore, the new regulations present challenges for surgical training and staff recruitment, risking the further fragmentation of training programs. Enhanced regional cooperation is proposed as a solution to ensure comprehensive training. This review explores the benefits of robotic-assisted minimally invasive esophagectomy (RAMIE) in improving surgical precision and patient outcomes and aims to evaluate how the caseload per year influences the quality of patient care and the efficacy of surgical training, especially with the integration of advanced robotic techniques.

Current status and prospects of diagnosis and treatment for esophageal cancer with supraclavicular lymph node metastasis

Patients with supraclavicular lymph node (SLN) metastasis from esophageal cancer encounter significant variations in treatment approaches due to differences in pathological subtypes and the lack of a unified regional staging system between East Asian and Western countries. The Tiger study aims to develop an internationally recognized staging system and to delineate the extent of regional lymph node dissection. In the context of esophageal squamous cell carcinoma (SCC) with SLN metastasis, the treatment paradigms from East Asia offer valuable insights. The Japan Esophageal Society (JES) 12th edition staging system guides a tailored comprehensive treatment strategy, emphasizing either radiotherapy and chemotherapy or surgical intervention. In contrast, esophageal adenocarcinoma (AC) predominates in Western countries, where the 8th edition of the American Joint Committee on Cancer (AJCC) staging system classifies SLN metastasis as a distant metastasis, advocating for systemic therapy as the primary treatment modality. Nonetheless, compelling evidence suggests that a multidisciplinary treatment approach, incorporating either radiotherapy and chemotherapy or surgery as the initial treatment, can yield superior outcomes for these patients compared to chemotherapy alone.

Multicentre randomized clinical trial on robot-assisted versus video-assisted thoracoscopic oesophagectomy (REVATE trial)

BACKGROUND

Surgery for oesophageal squamous cell carcinoma involves dissecting lymph nodes along the recurrent laryngeal nerve. This is technically challenging and injury to the recurrent laryngeal nerve may lead to vocal cord palsy, which increases the risk of pulmonary complications. The aim of this study was to compare the efficacy and safety of robot-assisted oesophagectomy (RAO) versus video-assisted thoracoscopic oesophagectomy (VAO) for dissection of lymph nodes along the left RLN.

METHODS

Patients with oesophageal squamous cell carcinoma who were scheduled for minimally invasive McKeown oesophagectomy were allocated randomly to RAO or VAO, stratified by centre. The primary endpoint was the success rate of left recurrent laryngeal nerve lymph node dissection. Success was defined as the removal of at least one lymph node without causing nerve damage lasting longer than 6 months. Secondary endpoints were perioperative and oncological outcomes.

RESULTS

From June 2018 to March 2022, 212 patients from 3 centres in Asia were randomized, and 203 were included in the analysis (RAO group 103; VAO group 100). Successful left recurrent laryngeal nerve lymph node dissection was achieved in 88.3% of the RAO group and 69% of the VAO group (P < 0.001). The rate of removal of at least one lymph node according to pathology was 94.2% for the RAO and 86% for the VAO group (P = 0.051). At 1 week after surgery, the RAO group had a lower incidence of left recurrent laryngeal nerve palsy than the VAO group (20.4 versus 34%; P = 0.029); permanent recurrent laryngeal nerve palsy rates at 6 months were 5.8 and 20% respectively (P = 0.003). More mediastinal lymph nodes were dissected in the RAO group (median 16 (i.q.r. 12-22) versus 14 (10-20); P = 0.035). Postoperative complication rates were comparable between the two groups and there were no in-hospital deaths.

CONCLUSION

In patients with oesophageal squamous cell carcinoma, RAO leads to more successful left recurrent laryngeal nerve lymph node dissection than VAO, including a lower rate of short- and long-term recurrent laryngeal nerve injury. Registration number: NCT03713749 (http://www.clinicaltrials.gov).

Is Robotic Surgery the Future for Resectable Esophageal Cancer?: A Systematic Literature Review of Oncological and Clinical Outcomes

BACKGROUND

Radical esophagectomy for resectable esophageal cancer is a major surgical intervention, associated with considerable postoperative morbidity. The introduction of robotic surgical platforms in esophagectomy may enhance advantages of minimally invasive surgery enabled by laparoscopy and thoracoscopy, including reduced postoperative pain and pulmonary complications. This systematic review aims to assess the clinical and oncological benefits of robot-assisted esophagectomy.

METHODS

A systematic literature search of the MEDLINE (PubMed), Embase and Cochrane databases was performed for studies published up to 1 August 2023. This review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocols and was registered in the PROSPERO database (CRD42022370983). Clinical and oncological outcomes data were extracted following full-text review of eligible studies.

RESULTS

A total of 113 studies (n = 14,701 patients, n = 2455 female) were included. The majority of the studies were retrospective in nature (n = 89, 79%), and cohort studies were the most common type of study design (n = 88, 79%). The median number of patients per study was 54. Sixty-three studies reported using a robotic surgical platform for both the abdominal and thoracic phases of the procedure. The weighted mean incidence of postoperative pneumonia was 11%, anastomotic leak 10%, total length of hospitalisation 15.2 days, and a resection margin clear of the tumour was achieved in 95% of cases.

CONCLUSIONS

There are numerous reported advantages of robot-assisted surgery for resectable esophageal cancer. A correlation between procedural volume and improvements in outcomes with robotic esophagectomy has also been identified. Multicentre comparative clinical studies are essential to identify the true objective benefit on outcomes compared with conventional surgical approaches before robotic surgery is accepted as standard of practice.

Short-term outcomes of robot-assisted versus conventional minimally invasive esophagectomy for esophageal cancer: a systematic review and meta-analysis of 18,187 patients

The role of robotic surgery in the curative-intent treatment of esophageal cancer patients is yet to be defined. To compare short-term outcomes between conventional minimally invasive (cMIE) and robot-assisted minimally invasive esophagectomy (RAMIE) in esophageal cancer patients. PubMed, Web of Science and Cochrane Library were systematically searched. The included studies compared short-term outcomes between cMIE and RAMIE. Individual risk of bias was calculated using the MINORS and RoB2 scales. There were no statistically significant differences between RAMIE and cMIE regarding conversion to open procedure, mean number of harvested lymph nodes in the mediastinum, abdomen and along the right recurrent laryngeal nerve (RLN), 30- and 90-day mortality rates, chyle leakage, RLN palsy as well as cardiac and infectious complication rates. Estimated blood loss (MD - 71.78 mL, p < 0.00001), total number of harvested lymph nodes (MD 2.18 nodes, p < 0.0001) and along the left RLN (MD 0.73 nodes, p = 0.03), pulmonary complications (RR 0.70, p = 0.001) and length of hospital stay (MD - 3.03 days, p < 0.0001) are outcomes that favored RAMIE. A significantly shorter operating time (MD 29.01 min, p = 0.004) and a lower rate of anastomotic leakage (RR 1.23, p = 0.0005) were seen in cMIE. RAMIE has indicated to be a safe and feasible alternative to cMIE, with a tendency towards superiority in blood loss, lymph node yield, pulmonary complications and length of hospital stay. There was significant heterogeneity among studies for some of the outcomes measured. Further studies are necessary to confirm these results and overcome current limitations.

Prognostic Factors for Recovery from Left Recurrent Laryngeal Nerve Palsy After Minimally Invasive McKeown Esophagectomy: A Retrospective Study

BACKGROUND

Recurrent laryngeal nerve (RLN) palsy is a serious complication of esophagectomy that affects the patient's phonation and the ability to prevent life-threatening aspiration events. The aim of this single-center, retrospective study was to investigate the clinical course of left RLN palsy and to identify the main prognostic factors for recovery.

METHODS

The study cohort consisted of 85 patients who had developed left RLN palsy after minimally invasive McKeown esophagectomy. Vocal cord function was assessed in all participants through laryngoscopic examinations, both in the immediate postoperative period and during follow-up. Permanent palsy was defined as no evidence of recovery after 6 months. Univariate and multivariable logistic regression analyses were applied to evaluate the associations between different variables and the outcome of palsy.

RESULTS

Twenty-two (25.8%) patients successfully recovered from left RLN palsy. On multivariable logistic regression analysis, active smoking (odds ratio [OR] 0.335, p = 0.038) and the use of thoracoscopic surgery (vs. robotic surgery; OR 0.264, p = 0.028) were identified as independent unfavorable predictors for recovery from palsy. The estimated rates of recovery derived from a logistic regression model for patients harboring two, one, or no risk factors were 13.16%, 31.15-34.75%, and 61.39%, respectively.

CONCLUSION

Only one-quarter of patients who had developed left RLN palsy after minimally invasive McKeown esophagectomy were able to fully recover. Smoking habits and the surgical approach were identified as key determinants of recovery. Patients harboring adverse prognostic factors are potential candidates for early intervention strategies.

Learning Curve of Robot-Assisted Lymph Node Dissection of the Left Recurrent Laryngeal Nerve: A Retrospective Study of 417 Patients

OBJECTIVE

Left recurrent laryngeal nerve (no.106recL) lymph node dissection is a challenging procedure, and robotic-assisted minimally invasive esophagectomy (RAMIE) may have some advantages. This study aimed to determine the learning curve of no.106recL lymph node dissection.

METHODS

The data of 417 patients who underwent McKeown RAMIE between June 2017 and June 2022 were retrospectively analyzed. The lymph node harvest of no.106recL was used to determine the learning curve, and the cumulative sum (CUSUM) method was employed to obtain the inflection point.

RESULTS

A total of 404 patients (404/417, 96.9%) underwent robotic surgery. Based on the number of no.106recL lymph nodes harvested, the CUSUM learning curve was mapped and divided into three phases: phase I (1‒75 cases), phase II (76‒240 cases), and phase III (241‒404 cases). The median (IQR) number of no.106recL lymph node harvests were 1 (4), 3 (6,) and 4 (4) in each phase (p < 0.001). The lymph node dissection rate gradually increased from 62.7% in phase I to 82.9% in phase III (p = 0.001). The total and thoracic lymph node harvest gradually increased (p < 0.001), whereas operation time (p = 0.001) and blood loss gradually decreased (p < 0.001). Moreover, the incidence of total complication (p = 0.020) and recurrent laryngeal nerve injury (p = 0.001) significantly decreased, and the postoperative hospital stay gradually shortened (p < 0.001).

CONCLUSION

Robotic no.106recL lymph node dissection has some advantages for patients with esophageal cancer. In this study, perioperative and clinical outcomes were significantly improved over the learning curve. However, further prospective studies are required to confirm our results.

Perioperative Outcomes and Learning Curve of Robot-Assisted McKeown Esophagectomy

BACKGROUND

This study aimed to evaluate the perioperative outcomes of patients undergoing robot-assisted McKeown esophagectomy (RAME) and the learning curves of surgeons performing RAME at a single center.

METHODS

Perioperative outcomes of RAME and video-assisted McKeown esophagectomy (VAME) were compared after eliminating confounding factors by propensity score matching (PSM). The cumulative sum (CUSUM) method was used to evaluate the learning curves of RAME for a single surgical team.

RESULTS

In general, a total of 198 patients with esophageal cancer (RAME: 45 patients, VAME: 153 patients) were included in this study, and 43 pairs of patients receiving RAME or VAME were matched using 1:1 PSM analysis. Those in the RAME group had more lymph nodes dissected in the total lymph nodes (median 29.0 vs. 26.0, P = 0.011) and the upper mediastinum (median 8.0 vs. 6.0, P < 0.001), especially the left recurrent laryngeal nerve (RLN) lymph node (median 4.0 vs. 2.0, P = 0.001). According to the trend of the CUSUM plot, the learning curve was divided into two stages at the 20th RAME procedure. After mastering the learning curve, RAME harvested a significantly higher number of upper mediastinal lymph nodes (median 9.0 vs. 6.0, P = 0.001), left RLN lymph nodes (median 5.0 vs. 3.5, P = 0.003), and right RLN lymph nodes (median 4.0 vs. 2.0, P = 0.002). Meanwhile, the incidence of postoperative pneumonia in the proficiency phase was significantly lower than that in the learning phase (4.0% vs. 25.0%, P = 0.04).

CONCLUSIONS

RAME improved left RLN lymph node dissection. Surgeons with extensive VAME experience need at least 20 cases to achieve early proficiency in RAME.

Implementation of the Esophagectomy Complication Consensus Group definitions: the benefits of speaking the same language

In 2015 the Esophagectomy Complication Consensus Group (ECCG) reported consensus definitions for complications after esophagectomy. This aimed to reduce variation in complication reporting, attributed to heterogeneous definitions. This systematic review aimed to describe the implementation of this definition set, including the effect on complication frequency and variation. A systematic literature review was performed, identifying all observational and randomized studies reporting complication frequencies after esophagectomy since the ECCG publication. Recruitment periods before and subsequent to the index ECCG publication date were included. Coefficients of variance were calculated to assess outcome heterogeneity. Of 144 studies which met inclusion criteria, 70 (48.6%) used ECCG definitions. The median number of separately reported complication types was five per study; only one study reported all ECCG complications. The coefficients of variance of the reported frequencies of eight of the 10 most common complications were reduced in studies which used the ECCG definitions compared with those that did not (P = 0.036). Among ECCG studies, the frequencies of postoperative pneumothorax, reintubation, and pulmonary emboli were significantly reduced in 2020-2021, compared with 2015-2019 (P = 0.006, 0.034, and 0.037 respectively). The ECCG definition set has reduced variation in esophagectomy morbidity reporting. This adds greater confidence to the observed gradual improvement in outcomes with time, and its ongoing use and wider dissemination should be encouraged. However, only a handful of outcomes are widely reported, and only rarely is it used in its entirety.

McKeown esophagectomy: robot-assisted versus conventional minimally invasive technique-systematic review and meta-analysis

BACKGROUND AND PURPOSE

This meta-analysis assesses the surgical outcomes between robot-assisted minimally-invasive McKeown esophagectomy and conventional one.

METHOD

This meta-analysis searched the Web of Science, PUBMED, and EMBASE from the database's inception to January 2022. Altogether, 1073 records were identified in the literature search. Studies that evaluated the outcomes between robot-assisted minimally-invasive McKeown esophagectomy and conventional one among postoperative patients with oesophageal neoplasms were included. The assessed outcomes involved complications and clinical outcomes. In addition, heterogeneity was analyzed, and evidence quality was evaluated.

RESULT

Evidence indicated that RAMIE (minimally-invasive esophagectomy assisted with robot) decreased incidences of lung complications and hospital stay as well as increased harvested lymph nodes.

CONCLUSIONS

There was currently little evidence from randomized studies depicting that robot surgery manifested a clear overall advantage, but there was growing evidence regarding the clinical benefits of robot-assisted minimally invasive McKeown esophagectomy over conventional one.

End to side circular stapled anastomosis during robotic-assisted Ivor Lewis minimally invasive esophagectomy (RAMIE)

Robotic-assisted minimally invasive esophagectomy (RAMIE) represents an established approach for the treatment of esophageal cancer. Aim of this study is to evaluate the feasibility and safety of our technique for performing the intrathoracic anastomosis during RAMIE.All the procedures were performed by the same surgeon using the same technique for performing the intrathoracic anastomosis. Intraoperative and postoperative outcomes were recorded. Postoperative complications were classified according to the Esophagectomy Complications Consensus Group (ECCG); the primary outcome was the evaluation of the feasibility and safety of our technique. From 2016 to 2021, 204 patients underwent Ivor Lewis RAMIE at our Center. Two patients (0.9%) were converted during the thoracic phase. The anastomosis was completed in all the other patients forming complete anastomotic rings. The median duration for the robotic-assisted thoracoscopic phase was 224 minutes. Twenty-two of the RAMIE-Ivor Lewis patients had an anastomotic leakage (10.3%). The overall 90-day postoperative mortality was 1.9%. The procedure resulted to be feasible and safe in our cohort of patients.

Meta-analysis of robot-assisted versus video-assisted McKeown esophagectomy for esophageal cancer

We aim to review the available literature on patients with esophageal cancer treated with robot-assisted (RAME) or video-assisted McKeown's esophagectomy (VAME), to compare the efficacy and safety of the two approaches. Original research studies that evaluated perioperative and oncologic outcomes of RAME versus VAME were identified, from January 1990 to July 2022. The 90-day mortality, the R0 resection rate, the dissected lymph nodes, the perioperative parameters, and the complications were calculated according to a fixed and a random effect model. The Q statistics and I² statistic were used to test for heterogeneity among the studies. Seven studies were included, incorporating a total of 1617 patients treated with RAME or VAME. The 90-day mortality was similar between the two groups. No difference was found regarding the R0 resection rate and the number of dissected lymph nodes. In addition, the perioperative parameters, along with the total complications were similar between RAME and VAME. Nonetheless, the incidence of postoperative pneumonia was higher in the VAME group (OR:0.67 [95% CI: 0.49, 0.93]; p = 0.02). Finally, our outcomes were further validated by sensitivity analysis including only studies performing propensity score-matched analysis. Our meta-analysis showed that RAME was equivalent to VAME in terms of safety, feasibility, and oncologic adequacy. These results should be interpreted with caution due to the small number of included studies. New Randomized Controlled trials, that are currently active, will provide further evidence with greater clarity to assess the effectiveness and safety of RAME for esophageal cancer.

Patterns of Recurrence After Robot-Assisted Minimally Invasive Esophagectomy in Esophageal Squamous Cell Carcinoma

Robot-assisted minimally invasive esophagectomy (RAMIE) has been proven to be a feasible surgical approach for esophageal squamous cell carcinoma (ESCC). This study aimed to investigate the recurrence pattern and potential risk factors after RAMIE. Consecutive patients with ESCC who received RAMIE with McKeown technique at a single Esophageal Cancer Institute from November 2015 to September 2018 were retrospectively reviewed. Patients with available data, radical resection (R0), and a minimum 2-year follow-up period were eligible for the recurrence analysis. Risk factors of recurrence were examined by logistic regression analysis. R0 resection was achieved in 95.1% of patients (310/326). Of the 298 eligible patients with a median follow-up period of 30.6 months, recurrence was recognized in 95 patients (31.9%), with 4 (1.3%) local-only, 40 (13.4%) regional-only, 44 (14.8%) hematogenous-only and 7 (2.3%) combined recurrences. Cervical lymph nodes and lungs were the most frequent sites of regional and hematogenous recurrence, respectively. The median disease-free interval until recurrence was 12.1 (range 1.7-37.6) months and 83.2% of relapses occurred within 2 years after surgery. Multivariable analysis indicated that tumor in the upper esophagus, larger tumor length and positive lymph nodes as independent risk factors for recurrence. Hematogenous recurrence is the prevailing pattern after RAMIE for ESCC. For patients with advanced disease, neoadjuvant therapy is a key factor in reducing recurrence rather than surgical approaches.

Robot-assisted versus video-assisted thoraco-laparoscopic McKeown's esophagectomy for esophageal cancer: a propensity score-matched analysis of minimally invasive approaches

Minimally invasive esophagectomy for esophageal cancer decreases overall complication rate and leads to faster postoperative recovery. Robot-assisted minimally invasive esophagectomy is becoming more common. Its three-dimensional view and wristed instruments may provide advantages over traditional thoraco-laparoscopic techniques. There are limited studies comparing robotic and conventional thoraco-laparoscopic esophagectomy. This study aimed to evaluate short-term outcomes of robot-assisted McKeown esophagectomy (RAME) and video-assisted McKeown esophagectomy (VAME). All consecutive patients undergoing minimally invasive McKeown esophagectomy for middle and distal third esophageal cancer between January 2016 and December 2018 at our center were included in this study. Data on baseline characteristics, pathological data and short-term outcomes were collected in a dedicated database. Postoperative complications were defined as per recommendations of Esophagectomy Complications Consensus Group. Histopathologic assessment was performed as per College of American Pathologists guidelines. Propensity score matching was performed for comparison between RAME and VAME groups using age, gender, performance status, American Society of Anesthesiologists grade, body mass index, Charlson Index, tumor location, clinical tumor stage, and neoadjuvant treatment as covariates. A total of 74 patients were included, 25 of whom underwent RAME and 49 underwent VAME. Propensity score matching on 1:1 basis produced 25 pairs of patients, comparable in terms of baseline characteristics. Total operative time and estimated blood loss was similar between the two groups. Length of hospital stay was significantly lower in RAME group. Major postoperative complications (Clavien-Dindo grade ≥ 3A) were more common in VAME group, but not statistically significant. Median number of harvested lymph nodes and R0 resection rate did not differ in between the two groups. In our experience, robot-assisted McKeown esophagectomy was comparable to video-assisted McKeown esophagectomy in terms of safety, feasibility and oncologic adequacy. Use of the robot was associated with reduced hospital stay. Further randomized controlled studies with larger patient samples are needed to compare the two.

Comparison of Clinical Outcomes of Robot-Assisted, Video-Assisted, and Open Esophagectomy for Esophageal Cancer: A Systematic Review and Meta-analysis

IMPORTANCE

The utilization of robot-assisted minimally invasive esophagectomy (RAMIE) for esophageal cancer is increasing, despite limited data comparing RAMIE with other surgical approaches.

OBJECTIVE

To evaluate the literature for clinical outcomes of RAMIE compared with video-assisted minimally invasive esophagectomy (VAMIE) and open esophagectomy (OE).

DATA SOURCES

A systematic search of PubMed, Cochrane, Ovid Medline, and Embase databases from January 1, 2013, to May 6, 2020, was performed.

STUDY SELECTION

Studies that compared RAMIE with VAMIE and/or OE for cancer were included.

DATA EXTRACTION AND SYNTHESIS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) reporting guideline, data were extracted by independent reviewers. A random-effects meta-analysis of 9 propensity-matched studies was performed for the RAMIE vs VAMIE comparison only. A narrative synthesis of RAMIE vs VAMIE and OE was performed.

MAIN OUTCOMES AND MEASURES

The outcomes of interest were intraoperative outcomes (ie, estimated blood loss [EBL], operative time, lymph node [LN] harvest), short-term outcomes (anastomotic leak, recurrent laryngeal nerve [RLN] palsy, pulmonary and total complications, and 90-day mortality), and long-term oncologic outcomes.

RESULTS

Overall, 21 studies (2 randomized clinical trials, 11 propensity-matched studies, and 8 unmatched studies) with 9355 patients were included. A meta-analysis was performed with 9 propensity-matched studies comparing RAMIE with VAMIE. The random-effects pooled estimate found an adjusted risk difference (RD) of -0.06 (95% CI, -0.11 to -0.01) favoring fewer pulmonary complications with RAMIE. There was no evidence of differences between RAMIE and VAMIE in LN harvest (mean difference [MD], -1.1 LN; 95% CI, -2.45 to 0.25 LNs), anastomotic leak (RD, 0.0; 95% CI, -0.03 to 0.03), EBL (MD, -6.25 mL; 95% CI, -18.26 to 5.77 mL), RLN palsy (RD, 0.01; 95% CI, -0.08 to 0.10), total complications (RD, 0.05; 95% CI, -0.01 to 0.11), or 90-day mortality (RD, -0.01; 95% CI, -0.02 to 0.0). There was low certainty of evidence that RAMIE was associated with a longer disease-free survival compared with VAMIE. For OE comparisons (data not pooled), RAMIE was associated with a longer operative time, decreased EBL, and less pulmonary and total complications.

CONCLUSIONS AND RELEVANCE

In this study, RAMIE had similar outcomes as VAMIE but was associated with fewer pulmonary complications compared with VAMIE and OE. Studies on long-term functional and cancer outcomes are needed.

Robot-assisted minimally invasive esophagectomy versus video-assisted minimally invasive esophagectomy: a systematic review and meta-analysis

Background

Robot-assisted minimally invasive esophagectomy (RAMIE) has been demonstrated to offer realistic three-dimensional visual clarity, flexible movement and so on. The high cost is the main reason hampering universal application. The aim of this study was to compare the short-term outcomes of RAMIE versus video-assisted minimally invasive esophagectomy (VAMIE).

Methods

The PubMed, EMBASE and Web of Science databases were systematically searched up to June 1, 2021, for studies comparing RAMIE and VAMIE.

Results

Nineteen studies were enrolled, which consisted of a total of 4,714 patients, including 2,306 patients in the RAMIE group and 2,408 patients in the VAMIE group. In RAMIE patients, higher numbers of total lymph nodes (MD =0.171, 95% CI: 0.086–0.255, P<0.001) and lymph nodes along the left recurrent laryngeal nerve (RLN) (MD =0.219, 95% CI: 0.097–0.340, P<0.001) were removed. In RAMIE patients in the McKown group, higher numbers of total lymph nodes (MD =0.173, 95% CI: 0.080–0.265, P<0.001) and lymph nodes along the left RLN (MD =0.220, 95% CI: 0.090–0.350, P=0.001) were removed, while in those in the ESCC group, higher numbers of total lymph nodes (MD =0.249, 95% CI: 0.091–0.407, P=0.002) and lymph nodes along the left RLN (MD =0.239, 95% CI: 0.102–0.377, P=0.001) were removed.

Discussion

This study indicated that the main advantage of RAMIE was a greater number of harvested lymph nodes, which may be beneficial to diagnosis and local control. RCTs with larger sample sizes and studies reporting long-term outcomes are needed to evaluate the advantages and disadvantages of RAMIE and VAMIE.

Improving Outcome of Superior Mediastinal Lymph Node Dissection During Esophagectomy: A Novel Approach Combining Continuous and Intermittent Recurrent Laryngeal Nerve Monitoring

OBJECTIVE

This study aimed at demonstrating the effects and learning curve of utilizing combined intermittent and continuous recurrent laryngeal nerve (RLN) monitoring for lymphadenectomy during esophagectomy.

BACKGROUND

RLN lymphadenectomy is oncologically important but is technically demanding. Vocal cord (VC) palsy as a result from RLN injury, carries significant morbidities.

METHODS

This is a retrospective study of consecutive esophageal squamous cell carcinoma (ESCC) patients who underwent transthoracic esophagectomy from 2010 to 2020. Combined nerve monitoring (CNM) included: CNM which involved a periodic stimulating left vagal electrode and intermittent nerve monitoring which utilized a stimulating probe to identify the RLNs. The integrity of the RLNs was assessed both intermittently and continuously. This technique was introduced in 2014. Patients were divided into "before CNM" and "CNM" groups. The primary outcome was the difference in number of RLN lymph nodes harvested and VC palsy rate. Learning curves were demonstrated by cumulative sum (CUSUM) analysis.

RESULTS

Two hundred and fifty-five patients were included with 157 patients in "CNM" group. The mean number of RLN lymph nodes harvested was significantly higher (4.31 vs 0.45, P < 0.0001) for the "CNM" group. VC palsy rates were significantly lower (17.8% vs 32.7%, P = 0.007). There was an initial increase in VC palsy rate, peaked at around 46 cases. The increase in lymph nodes harvested above the mean plateaued at around 96 cases.

CONCLUSIONS

CNM helped improve bilateral RLN lymphadenectomy. Lymph node harvesting was increased with reduction of VC palsy after a learning curve.

Robot-assisted minimally invasive thoraco-laparoscopic esophagectomy versus minimally invasive esophagectomy for resectable esophageal adenocarcinoma, a randomized controlled trial (ROBOT-2 trial)

BACKGROUND

For patients with esophageal adenocarcinoma or cancer of the gastroesophageal junction, radical esophagectomy with 2-field lymphadenectomy is the cornerstone of the multimodality treatment with curative intent. Both conventional minimally invasive esophagectomy (MIE) and robot assisted minimally invasive esophagectomy (RAMIE) were shown to be superior compared to open transthoracic esophagectomy considering postoperative complications. However, no randomized comparison exists between MIE and RAMIE in the Western World for patients with esophageal adenocarcinoma.

METHODS

This is an investigator-initiated and investigator-driven multicenter randomized controlled parallel-group superiority trial. All adult patients (age ≥ 18 and ≤ 90 years) with histologically proven, surgically resectable (cT1-4a, N0-3, M0) esophageal adenocarcinoma of the intrathoracic esophagus or adenocarcinoma of the gastroesophageal junction and with European Clinical Oncology Group performance status 0, 1 or 2 will be assessed for eligibility and included after obtaining informed consent. Patients (n = 218) with resectable esophageal adenocarcinoma of the intrathoracic esophagus or adenocarcinoma of the gastroesophageal junction are randomized to either RAMIE (n = 109) or MIE (n = 109). The primary outcome of this study is the total number of resected abdominal and mediastinal lymph nodes specified per lymph node station.

CONCLUSION

This is the first randomized controlled trial designed to compare RAMIE to MIE as surgical treatment for resectable esophageal adenocarcinoma or adenocarcinoma of the gastroesophageal junction in the Western World. The hypothesis of the proposed study is that RAMIE will result in a higher abdominal and mediastinal lymph node yield specified per station compared to conventional MIE. Short-term results and the primary endpoint (total number of resected abdominal and mediastinal lymph nodes per lymph node station) will be analyzed and published after discharge of the last randomized patient within this trial.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier: NCT04306458 . Registered 13th March 2020, https://clinicaltrials.gov/ct2/show/NCT04306458; Date of first enrolment 18.01.2021; Target sample size 218; Recruitment status: Recruiting; Protocol version 2; Issue date 10.03.2020; Rev. 02.02.2021; Authors ET, PCvdS, PPG.

Totally Robotic Esophagectomy

Totally robotic esophagectomy is performed using a robotic technique without additional thoracoscopy or laparoscopy. However, most robotic esophagectomies are currently performed in a hybrid form combining robotic and other endoscopic techniques. Laparoscopic stomach mobilization and thoracoscopic esophagogastric anastomosis are commonly used methods in robotic esophagectomy. In this paper, totally robotic esophagectomy without thoracoscopic or laparoscopic assistance is presented.

Robotic Esophagectomy. A Systematic Review with Meta-Analysis of Clinical Outcomes

Background: Robot-Assisted Minimally Invasive Esophagectomy is demonstrated to be related with a facilitation in thoracoscopic procedure. To give an update on the state of art of robotic esophagectomy for cancr a systematic review with meta-analysis has been performed. Methods: a search of the studies comparing robotic and laparoscopic or open esophagectomy was performed trough the medical libraries, with the search string “robotic and (oesophagus OR esophagus OR esophagectomy OR oesophagectomy)”. Outcomes were: postoperative complications rate (anastomotic leakage, bleeding, wound infection, pneumonia, recurrent laryngeal nerves paralysis, chylotorax, mortality), intraoperative outcomes (mean blood loss, operative time and conversion), oncologic outcomes (harvested nodes, R0 resection, recurrence) and recovery outcomes (length of hospital stay). Results: Robotic approach is superior to open surgery in terms of blood loss p = 0.001, wound infection rate, p = 0.002, pneumonia rate, p = 0.030 and mean number of harvested nodes, p < 0.0001 and R0 resection rate, p = 0.043. Similarly, robotic approach is superior to conventional laparoscopy in terms of mean number of harvested nodes, p = 0.001 pneumonia rate, p = 0.003. Conclusions: robotic surgery could be considered superior to both open surgery and conventional laparoscopy. These encouraging results should promote the diffusion of the robotic surgery, with the creation of randomized trials to overcome selection bias.

Robot-Assisted Versus Conventional Minimally Invasive Esophagectomy for Resectable Esophageal Squamous Cell Carcinoma: Early Results of a Multicenter Randomized Controlled Trial: the RAMIE Trial

OBJECTIVE

To compare perioperative and long-term outcomes of robot-assisted minimally invasive esophagectomy (RAMIE) and conventional minimally invasive esophagectomy (MIE) in the treatment for patients with esophageal squamous cell carcinoma (ESCC).

SUMMARY BACKGROUND DATA

RAMIE has emerged as an alternative to traditional open or thoracoscopic approaches. Efficacy and safety of RAMIE and MIE in the surgical treatment for ESCC remains uncertain given the lack of high-level clinical evidence.

METHODS

The RAMIE trial was designed as a prospective, multicenter, randomized, controlled clinical trial that compare the efficacy and safety of RAMIE and MIE in the treatment of resectable ESCC. From August 2017 to December 2019, eligible patients were randomly assigned to receive either RAMIE or MIE performed by experienced thoracic surgeons from six high-volume centers in China. Intent-to-treat analysis was performed.

RESULTS

Significantly shorter operation time was taken in RAMIE (203.8 vs. 244.9 mins, P<0.001). Compared to MIE, RAMIE showed improved efficiency of thoracic lymph node dissection in patients who received neoadjuvant therapy (15 vs. 12, P=0.016), as well as higher achievement rate of lymph node dissection along the left recurrent laryngeal nerve (RLN) (79.5% vs. 67.6%, P=0.001). No difference was found in blood loss, conversion rate, and R0 resection. The 90-day mortality was 0.6% in each group. Overall complications were similar in RAMIE (48.6%) compared to MIE (41.8%) (RR, 1.16; 95% CI, 0.92-1.46; P=0.196). Besides, the rate of major complications (Clavien-Dindo classification ≥ III) was also comparable (12.2% vs. 10.2%, P=0.551). RAMIE showed similar incidences of pulmonary complications (13.8% vs. 14.7%; P=0.812), anastomotic leakage (12.2% vs. 11.3%; P=0.801) and vocal cord paralysis (32.6% vs. 27.1%, P=0.258) to MIE.

CONCLUSIONS

Early results demonstrate that both RAMIE and MIE are safe and feasible for the treatment of ESCC. RAMIE can achieve shorter operative duration as well as better lymph node dissection in patients who received neoadjuvant therapy. Long-term results are pending for further follow-up investigations.

TRIAL REGISTRATION

ClinicalTrial.gov Identifier: NCT03094351.

Incidence of Recurrent Laryngeal Nerve Palsy in Robot-Assisted Versus Conventional Minimally Invasive McKeown Esophagectomy in Prone Position: A Propensity Score-Matched Study

BACKGROUND

Esophagectomy with lymphadenectomy is the principal treatment for localized esophageal cancer. Conventional minimally invasive esophagectomy (C-MIE) in prone position has spread worldwide as it is less invasive. However, its efficacy remains controversial. Robot-assisted MIE (RAMIE) can have more advantages than C-MIE. Therefore, the current study aimed to validate whether RAMIE is associated with lower incidence of left recurrent laryngeal nerve (RLN) palsy compared with C-MIE in prone position.

PATIENTS AND METHODS

In total, 404 patients with esophageal carcinoma underwent MIE (353 C-MIEs and 51 RAMIEs) in prone position at Kobe University between 2010 and 2020. Then, propensity score matching was performed, and results showed that 51 patients should be included in each group. Thereafter, the perioperative outcomes between the two groups were compared.

RESULTS

The RAMIE group had a significantly longer operative time than the C-MIE group (P < 0.0001). However, the number of lymph nodes resected along the left RLN was similar in both groups. Moreover, the incidence of left RLN palsy was significantly lower in the RAMIE group than in the C-MIE [Clavien-Dindo classification grade II; 0 (0%) versus 32 (9%), P = 0.022 in entire cohort, and 0 (0%) versus 5 (10%), P = 0.022 in matched cohort. Esophagectomy Complications Consensus Group definitions type I; 8 (16%) versus 101 (29%), P = 0.041 in entire cohort and 8 (16%) versus 18 (35%) in matched cohort, P = 0.023].

CONCLUSION

RAMIE is superior to C-MIE in prone position in decreasing the incidence of left RLN palsy.

Outcomes of Esophageal Cancer after Esophagectomy in the Era of Early Injection Laryngoplasty

(1) Background: severe weight loss was reported to be related to unilateral vocal fold paralysis (UVFP) after esophagectomy and could thus impair survival. Concomitant radical lymph node dissection along the recurrent laryngeal nerve during esophageal cancer surgery is controversial, as it might induce UVFP. Early intervention for esophagectomy-related UVFP by administering intracordal injections of temporal agents has recently become popular. This study investigated the survival outcomes of esophagectomy for esophageal squamous cell carcinoma (ESCC) after the introduction of early injection laryngoplasty (EIL). (2) Methods: a retrospective review of patients with ESCC after curative-intent esophagectomy was conducted in a tertiary referral medical center. The necessity of EIL with hyaluronic acid was comprehensively discussed for all symptomatic UVFP patients. The survival outcomes and related risk factors of ESCC were evaluated. (3) Results: among the cohort of 358 consecutive patients who underwent esophagectomy for ESCC, 42 (11.7%) showed postsurgical UVFP. Twenty-nine of them received office-based EIL. After EIL, the glottal gap area, maximum phonation time and voice outcome survey showed significant improvement at one, three and six months measurements. The number of lymph nodes in the resected specimen was higher in those with UVFP than in those without UVFP (30.1 ± 15.7 vs. 24.6 ± 12.7, p = 0.011). The Kaplan-Meier overall survival was significantly better in patients who had UVFP (p = 0.014), received neck anastomosis (p = 0.004), underwent endoscopic resection (p < 0.001) and had early-stage cancer (p < 0.001). Multivariate Cox logistic regression analysis showed two independent predictors of OS, showing that the primary stage and anastomosis type are the two independent predictors of OS. (4) Conclusion: EIL is effective in improving UVFP-related symptoms, thus providing compensatory and palliative measures to ensure the patient's postsurgical quality of life. The emerging use of EIL might encourage cancer surgeons to radically dissect lymph nodes along the recurrent laryngeal nerve, thus changing the survival trend.

Lower local recurrence rate after robot-assisted thoracoscopic esophagectomy than conventional thoracoscopic surgery for esophageal cancer

The oncological advantages of robot-assisted thoracoscopic esophagectomy (RATE) over conventional thoracoscopic esophagectomy (TE) for thoracic esophageal cancer have yet to be verified. In this study, we retrospectively analyzed clinical data to compare the incidences of recurrence within the surgical field after RATE and TE as an indicator of local oncological control. Among 121 consecutive patients with thoracic esophageal or esophagogastric junction cancers for which thoracoscopic surgery was indicated, 51 were treated with RATE while 70 received TE. The number of lymph nodes dissected from the mediastinum, duration of the thoracic portion of the surgery, and morbidity due to postoperative complications did not differ between the two groups. However, the rate of overall local recurrence within the surgical field was significantly (P = 0.039) higher in the TE (9%) than the RATE (0%) group. Lymph node recurrence within the surgical field occurred in left recurrent nerve, left tracheobronchial, left main bronchus and thoracic paraaortic lymph nodes, which were all difficult to approach to dissect. The other two local failures occurred around the anastomotic site. This study indicates that using RATE enabled the incidence of recurrence within the surgical field to be reduced, though there were some limitations.

Novel "Modified Bascule Method" for Lymphadenectomy Along the Left Recurrent Laryngeal Nerve During Robot-Assisted Minimally Invasive Esophagectomy

BACKGROUND

Given the worldwide popularization of conventional minimally invasive esophagectomy (C-MIE), robot-assisted MIE (RAMIE) can be expected to provide a finer procedure. However, controversy remains regarding whether RAMIE is superior to C-MIE in preventing recurrent laryngeal nerve (RLN) palsy. Considering the shallow learning curve for RAMIE, a novel procedure for lymphadenectomy along the RLN during RAMIE is needed.

METHODS

Based on a logical and simple understanding of the left upper mediastinum anatomy, the authors developed a novel "modified bascule method" for RAMIE that could simplify lymphadenectomy along the left RLN and prevent it from being touched and stretched. Between 2018 and 2020, 46 patients with esophageal carcinoma underwent RAMIE using this method at Kobe University.

RESULTS

The modified bascule method was used to perform RAMIE for 29 men and 17 women with a median age of 67 years (range, 49-82 years). The median thoracoscopic procedure time was 438 min (range, 344-625 min), and the median console time was 351 min (range 273-518 min). The study harvested a median of 24 (range, 8-34) lymph nodes from the thoracic portion and 4 (range, 0-10) lymph nodes from along the left RLN. The mortality rate was 0%. Postoperative left RLN palsy classified as Clavien-Dindo (C-D) grade 1 or higher was observed for 9 patients (19%), whereas grade 2 or higher was not seen (0%). Pneumonia and anastomotic leakage rates higher than C-D grade 2 were respectively 13% and 19%.

CONCLUSIONS

The novel modified bascule method for RAMIE can promote feasible lymphadenectomy along the left RLN even when performed during the learning period.

A standardized procedure for upper mediastinal lymph node dissection improves the safety and efficacy of robotic McKeown oesophagectomy

BACKGROUND

Recurrent laryngeal nerve (RLN) palsy is a common complication of upper mediastinal lymph node dissection (UMLND) in the context of oesophageal cancer surgery. In an effort to reduce its occurrence, we developed a standardised surgical procedure that allows flexible suspension of the left RLN during robotic McKeown oesophagectomy.

PATIENTS AND METHODS

Patients who received robotic McKeown oesophagectomy for cancer were divided into two groups (pre and poststandardisation). Perioperative outcomes were retrospectively compared.

RESULTS

The pre and poststandardisation groups consisted of 44 and 42 patients, respectively. There were no significant intergroup differences in terms of number of dissected lymph nodes. Compared with the prestandardisation group, patients treated after standardisation had a markedly lowered incidence of left RLN palsy (20.5% vs. 4.8%, respectively, p = 0.029) and a reduced mean thoracic operating time (161.05 vs. 131 min, respectively, p < 0.001).

CONCLUSION

Our standardised surgical approach is efficient and may increase the safety of UMLND.

Risk factors for lymph node metastasis of the left recurrent laryngeal nerve in patients with esophageal squamous cell carcinoma

Background

The factors for left recurrent laryngeal nerve (RLN) lymph node (LN) metastasis have important guiding significance for whether the left RLN LNs should be dissected in patients with esophageal squamous cell carcinoma (ESCC), but few studies are currently available. To analyze the risk factors of LN metastasis of the left RLN area and to assess which LNs should be dissected in ESCC.

Methods

This was a retrospective study of patients who underwent McKeown minimally invasive esophagectomy (MIE) (no neoadjuvant therapy) at Tianjin Medical University Cancer Institute and Hospital (from January 2016 to December 2019). The detection of left RLN LNs using enhanced computed tomography (CT) was compared with the pathological examination.

Results

Of the total 94 participants, 43 had LN metastasis. The metastatic LNs were mainly located next to left (18.1%) and right (14.9%) RLN, and the left gastric artery (13.8%). Tumor size, LN size, tumor invasion (T stage), N stage, and tumor node metastasis (TNM) stage were associated with left RLN LNs metastasis, while LN size was the only independently associated factor [odds ratio (OR) =1.569, 95% confidence interval (CI): 0.259–1.956, P=0.0012]. The area under receiver operating characteristic (ROC) curve (AUC) reached 0.877, with 64% sensitivity and 75% specificity using a cutoff of 5.5 mm LN size.

Conclusions

The size of left RLN LN is independently associated with metastasis. Left RLN LNs >5.5 mm at CT examination are more likely to be positive and should probably be dissected.

Propensity matched analysis of short term oncological and perioperative outcomes following robotic and thoracolaparoscopic esophagectomy for carcinoma esophagus- the first Indian experience

Thoracolaparoscopic esophagectomy (TLE) for carcinoma esophagus has better short-term outcomes compared to open esophagectomy. The precise role of robot-assisted laparoscopic esophagectomy (RALE) is still evolving. Single center retrospective analysis of TLE and RALE performed for carcinoma esophagus between January 2015 and September 2018. Propensity score matching was done between the groups for age, gender, BMI, ASA grade, tumor location, neoadjuvant therapy, the extent of surgical resection (Ivor Lewis or McKeown’s), histopathological type (squamous cell carcinoma or adenocarcinoma), clinical T and N stages. The primary outcome parameter was lymph node yield. Secondary outcome parameters were resection margin status, duration of surgery, blood loss, conversion to open procedure, length of hospital stay, length of ICU stay, complications, 90-day mortality and cost. There were 90 patients in TLE and 25 patients in RALE group. After propensity matching, there were 22 patients in each group. The lymph node yield was similar in both the groups (23.95 ± 8.23 vs 22.73 ± 11.63; p = 0.688). There were no conversions or positive resection margins in either group. RALE was associated with longer operating duration (513.18 ± 91.23 min vs 444.77 ± 64.91 min; p = 0.006) and higher cost ($5271.75 ± 456.46 vs $4243.01 ± 474.64; p < 0.001) than TLE. Both were comparable in terms of blood loss (138.86 ± 31.20 ml vs 133.18 ± 34.80 ml; p = 0.572), Clavien-Dindo grade IIIa and above complications (13.64% vs 9.09%; p = 0.634), hospital stay (12.18 ± 6.35 days vs 12.73 ± 7.83 days; p = 0.801), ICU stay (4.91 ± 5.22 days vs 4.77 ± 4.81 days; p = 0.929) and mortality (0 vs 4.55%; p = 0.235). RALE is comparable to TLE in terms of short-term oncological and perioperative outcomes except for longer operating duration when performed for carcinoma esophagus. RALE is costlier than TLE.

Does robot-assisted minimally invasive oesophagectomy have superiority over thoraco-laparoscopic minimally invasive oesophagectomy in lymph node dissection?

Although robotic techniques have been used for oesophagectomy for many years, whether robot-assisted minimally invasive oesophagectomy (RAMIE) can actually improve outcomes and surpass thoraco-laparoscopic minimally invasive oesophagectomy (MIE) in the success rate of lymph node dissection remains to be empirically demonstrated. Therefore, we performed this systematic review and meta-analysis of case-control studies to systematically compare the effect of lymph node dissection and the incidence of vocal cord palsy between RAMIE and MIE. The PubMed, EMBASE, and Web of Science databases were systematically searched up to December 1, 2019, for case-control studies that compared RAMIE with MIE. Thirteen articles were included, with a total of 1,749 patients with esophageal cancer, including 866 patients in the RAMIE group and 883 patients in the MIE group. RAMIE yielded significantly larger numbers of total dissected lymph nodes (WMD = 1.985; 95% CI, 0.448-3.523; P = 0.011) and abdominal lymph nodes (WMD = 1.686; 95% CI, 0.420-2.951; P = 0.009) as well as lymph nodes along RLN (WMD = 0.729; 95% CI, 0.348-1.109; P < 0.001) than MIE. Additionally, RAMIE could significantly decrease estimated blood loss (WMD = -11.208; 95% CI, -19.358 to -3.058; P = 0.007) and the incidence of vocal cord palsy (OR = 0.624; 95% CI, 0.411-0.947; P = 0.027) compared to MIE. Compared with MIE, RAMIE resulted in a higher total lymph node yield and a higher lymph node yield in the abdomen and along RLN, along with reduced blood loss during surgery and the incidence of vocal cord palsy. Therefore, RAMIE could be considered to be a standard treatment, with less blood loss, lower incidence of vocal cord palsy, and more radical lymph node dissection, exhibiting superiority over MIE.

Comparison of short-term clinical outcomes between robot-assisted minimally invasive esophagectomy and video-assisted minimally invasive esophagectomy: a systematic review and meta-analysis

Background

Though robot-assisted minimally invasive esophagectomy (RAMIE) is demonstrated to offer a better visualization and provide a fine dissection of the mediastinal structures to facilitate the complex thoracoscopic operation, the superiorities of RAMIE over MIE have not been well verified. The aim of this study was to explore the actual superiorities through comparing short-term results of RAMIE with that of MIE.

Methods

PubMed, EMBASE and web of science databases were systematically searched up to September 1, 2020 for case-controlled studies that compared RAMIE with TLMIE.

Results

Fourteen studies were identified, with a total of 2,887 patients diagnosed with esophageal cancer, including 1,435 patients subjected to RAMIE group and 1,452 patients subjected to MIE group. The operative time in RAMIE was still significantly longer than that in MIE group (OR =0.785; 95% CI, 0.618-0.952; P<0.001). The incidence of pneumonia was significantly lower in RAMIE group compared with MIE group (OR =0.677; 95% CI, 0.468-0.979; P=0.038).

Conclusions

RAMIE has the superiorities over MIE in short-term outcomes in terms of pneumonia and vocal cord palsy. Therefore, RAMIE could be considered as a standard treatment for patients with esophageal cancer.

Robot-Assisted Minimally Invasive Esophagectomy with Intrathoracic Anastomosis (Ivor Lewis): Promising Results in 100 Consecutive Patients (the European Experience)

BACKGROUND

Robot-assisted minimally invasive esophagectomy (RAMIE) with intrathoracic anastomosis is gaining popularity as a treatment for esophageal cancer. The aim of this study was to describe postoperative complications and short-term oncologic outcomes for RAMIE procedures using the da Vinci Xi robotic system 4-arm technique.

METHODS

Data of 100 consecutive patients with esophageal or gastro-esophageal junction carcinoma undergoing modified Ivor Lewis esophagectomy were prospectively collected. All operations were performed by the same surgeon using an identical intrathoracic anastomotic reconstruction technique with the same perioperative management. Intraoperative and postoperative complications were graded according to Esophagectomy Complications Consensus Group (ECCG) definitions.

RESULTS

Mean duration was 416 min (±80); 70% of patients had an uncomplicated postoperative recovery. Pulmonary complications were observed in 17% of patients. Anastomotic leakage was observed in 8% of patients. Median ICU stay was 1 day and median overall postoperative hospital stay was 11 days. The 30-day mortality was 1%; 90-day mortality was 3%. A R0 resection was reached in 92% of patients with a median number of 29 dissected lymph nodes. All patients had at least 7 months of follow-up with a median follow-up of 17 months. Median overall survival was not reached yet.

CONCLUSION

RAMIE with intrathoracic anastomosis (Ivor Lewis) for esophageal or gastro-esophageal junction cancer was technically feasible and safe. Postoperative complications and short-term oncologic results were comparable to the highest international standards nowadays.

Multicenter Experience in Robot-Assisted Minimally Invasive Esophagectomy - a Comparison of Hybrid and Totally Robot-Assisted Techniques

BACKGROUND

Oncological esophageal surgery has evolved significantly in the last decades. From open esophagectomy over (hybrid) minimally invasive surgery, nowadays, robot-assisted minimally invasive esophagectomy (RAMIE) approaches are applied. Current techniques require an analysis of possible advantages and disadvantages indicating the direction towards a novel gold standard.

METHODS

Robot-assisted Ivor Lewis esophagectomies, performed in the period from April 2017 to June 2019 in five German centers (Berlin, Cologne, Hamburg, Kiel, Mainz), were included in this study. Pre-, intra-, and postoperative parameters were assessed. Cases were grouped for hybrid (H-RAMIE) versus totally robot-assisted (T-RAMIE) approaches. Postoperative parameters and complications were compared using risk ratios.

RESULTS

A total of 175 operations were performed as T-RAMIE and 67 as H-RAMIE. Patient age (median age 62 years) and sex (83.1% male) were similarly distributed in both groups. Median duration of esophagectomy was significantly lower in the T-RAMIE group (385 versus 427 min, p < 0.001). The risks of "overall morbidity" (32.0 versus 47.8%; risk ratio [RR], 95% confidence interval (CI): 1.5, 1.1-2.1; p = 0.026), "anastomotic leak" (10.3 versus 22.4%; RR, CI: 2.2, 1.2-4.1; p = 0.020), and "respiratory failure" (1.1 versus 7.5%; RR, CI: 6.5, 1.3-32.9; p = 0.019) were significantly higher in case of H-RAMIE.

CONCLUSIONS

In the five participating German centers, T-RAMIE was the preferred procedure (72.3% of operations). In comparison to H-RAMIE, T-RAMIE was associated with a significantly reduced risk of postoperative morbidity, anastomotic leak, and respiratory failure as well as a significantly reduced time necessary for esophagectomy.

Robot-Assisted Esophagectomy After Neoadjuvant Chemoradiation-Current Status and Future Prospects

Multimodality treatment with neoadjuvant chemoradiation followed by surgery has become the standard of care for esophageal cancer. In the recent years, there has been a shift in focus of surgical approach from open esophagectomy to minimally invasive esophagectomy. Robot-assisted esophagectomy is being performed more often in centers across the world. However, there is limited data on role of robot-assisted esophagectomy in patients who have received neoadjuvant chemoradiation. Initial reports have shown that integrating neoadjuvant therapy to robot-assisted esophagectomy is feasible and safe. With the growing popularity of robot-assisted surgery worldwide among both surgeons and patients, understanding the impact of neoadjuvant chemoradiation on the procedure and its oncological outcome seems worthwhile. In the present study, we present a review of available literature on the feasibility and safety of robot-assisted minimally invasive esophagectomy in esophageal cancer patients after neoadjuvant chemoradiation.

Robot-assisted cervical esophagectomy: first clinical experiences and review of the literature

Pulmonary complications, and especially pneumonia, remain one of the most common complications after esophagectomy for esophageal cancer. These complications are reduced by minimally invasive techniques or by avoiding thoracic access through a transhiatal approach. However, a transhiatal approach does not allow for a full mediastinal lymphadenectomy. A transcervical mediastinal esophagectomy avoids thoracic access, which may contribute to a decrease in pulmonary complications after esophagectomy. In addition, this technique allows for a full mediastinal lymphadenectomy. A number of pioneering studies have been published on this topic. Here, the initial experience is presented as well as a review of the current literature concerning transcervical esophagectomy, with a focus on the robot-assisted cervical esophagectomy procedure.

Robotic McKeown esophagectomy with recurrent laryngeal nerve lymph node dissection: how I do it

We describe our standardized approach to robotic esophagectomy with special emphasis on the technical aspects pertaining to bilateral recurrent laryngeal nerve lymph node dissection.

A standardized approach for the thoracic dissection in robotic-assisted minimally invasive esophagectomy (RAMIE)

Robot-assisted minimally invasive esophagectomy (RAMIE) is increasingly being adopted as the preferred surgical treatment for esophageal cancer, as it is superior to open esophagectomy and a good alternative to conventional minimally invasive esophagectomy. This paper addresses the technical details of the thoracoscopic phase of RAMIE, including the operating room set-up, patient positioning, port placement, and surgical steps.

Specific complications and limitations of robotic esophagectomy

Regardless of the approach to esophagectomy, it is an operation that may be associated with significant risk to the patient. Robotic-assisted minimally invasive esophagectomy (RAMIE) has the same potential for short- and long-term complications as does open and minimally invasive esophagectomy. These complications include among others, the risk for anastomotic leak, gastric tip necrosis, vocal cord palsy, and chylothorax. Moreover, there are additional risks that are unique to the robotic platform such as hardware or software malfunction. These risks are heavily influenced by numerous factors including the patient's comorbidities, whether neoadjuvant therapy was administered, and the extent of the surgical team's experience. The limitations of RAMIE are therefore based on the careful assessment of the patient for operability, the tumor for resectability and the team for surgical ability. This article will tackle the topic of complications and limitations of RAMIE by examining each of these issues. It will also describe the recommended terminology for reporting post-esophagectomy complications.

Robot-assisted minimally invasive esophagectomy for esophageal cancer: Meticulous surgery minimizing postoperative complications

Minimally invasive esophagectomy (MIE) has been reported to reduce postoperative complications especially pulmonary complications and have equivalent long-term survival outcomes as compared to open esophagectomy. Robot-assisted minimally invasive esophagectomy (RAMIE) using da Vinci surgical system (Intuitive Surgical, Sunnyvale, USA) is rapidly gaining attention because it helps surgeons to perform meticulous surgical procedures. McKeown RAMIE has been preferably performed in East Asia where squamous cell carcinoma which lies in more proximal esophagus than adenocarcinoma is a predominant histological type of esophageal cancer. On the other hand, Ivor Lewis RAMIE has been preferably performed in the Western countries where adenocarcinoma including Barrett esophageal cancer is the most frequent histology. Average rates of postoperative complications have been reported to be lower in Ivor Lewis RAMIE than those in McKeown RAMIE. Ivor Lewis RAMIE may get more attention for thoracic esophageal cancer. The studies comparing RAMIE and MIE where recurrent nerve lymphadenectomy was thoroughly performed reported that the rate of recurrent nerve injury is lower in RAMIE than in MIE. Recurrent nerve injury leads to serious complications such as aspiration pneumonia. It seems highly probable that RAMIE is beneficial in performing recurrent nerve lymphadenectomy. Surgery for esophageal cancer will probably be more centralized in hospitals with surgical robots, which enable accurate lymph node dissection with less complications, leading to improved outcomes for patients with esophageal cancer. RAMIE might occupy an important position in surgery for esophageal cancer.

Lymph node dissection around left recurrent laryngeal nerve: robot-assisted vs. video-assisted McKeown esophagectomy for esophageal squamous cell carcinoma

OBJECTIVE

This study investigated the advantages of robot-assisted McKeown esophagectomy (RAME) for extensive superior mediastinal lymph node dissection (LND) versus video-assisted McKeown esophagectomy (VAME).

METHODS

The cases of 184 consecutive esophageal squamous cell carcinoma (ESCC) patients who underwent minimally invasive McKeown esophagectomy (109 with RAME, 75 with VAME) performed by a single surgical group between June 2017 and December 2019 were retrospectively reviewed.

RESULTS

Overall, 59.8% (110/181) patients (70 treated with RAME, 40 treated with VAME; 64.2% vs. 53.3%, respectively, p = 0.139) underwent complete LND around the left recurrent laryngeal nerve (RLN) by pathological assessment. Cumulative sum plots showed increased numbers of LND around the left RLN (3.6 ± 2.0 vs. 5.4 ± 2.7, p = 0.008) and a decreased incidence of recurrent nerve injury (27.9% vs. 7.4%, p = 0.037) after RAME learning curve. Despite similar overall LND results (30.6 ± 10.2 vs. 28.1 ± 10.2, p > 0.05), RAME yielded more LND (5.4 ± 2.7 vs. 4.4 ± 2.2, p = 0.016) and a greater proportion of lymph node metastases (37.0% vs. 7.5%) around the left RLN but induced a lower proportion of recurrent nerve injuries (7.4% vs. 22.5%, p = 0.178) compared with VAME. Further analysis revealed that the complete LND around the left RLN was associated with recurrent nerve injury in the RAME (20.0% vs. 5.1%, p = 0.035) and VAME (22.5% vs. 5.7%, p = 0.041) groups but did not affect other clinical outcomes including surgical duration, intraoperative blood loss, postoperative intensive care unit stay, hospital stay, and other complications.

CONCLUSIONS

For patients with ESCC, RAME has great advantages in LND around the left RLN and recurrent nerve protection after learning curve of robotic esophagectomy.

Adequate Lymphadenectomy as a Quality Measure in Esophageal Cancer: Is there an Association with Treatment Approach?

BACKGROUND

The national comprehensive cancer network defines adequate lymphadenectomy as evaluation of ≥ 15 lymph nodes in esophageal cancer. However, varying thresholds have been suggested following neoadjuvant therapy.

OBJECTIVES

Our objectives were to (1) explore trends in adequate lymphadenectomy rates over time; (2) evaluate unadjusted lymphadenectomy yield by treatment characteristics; and (3) identify independent factors associated with adequate lymphadenectomy.

METHODS

The National Cancer Data Base was used to identify patients who underwent esophagectomy for cancer from 2004 to 2015. Adequate lymphadenectomy trends over time were evaluated using the Cochrane-Armitage test, and lymph node yield by treatment approach was compared using the Mann-Whitney U and Kruskal-Wallis tests. Associations with treatment factors were assessed by multivariable logistic regression.

RESULTS

Among 24,413 patients, 9919 (40.6%) had adequate lymphadenectomy. Meeting the nodal threshold increased over time (52.6% in 2015 vs. 26.0% in 2004; p < 0.01). Lymph node yield did not differ based on neoadjuvant therapy (median 12 [interquartile range 7-19] with and without neoadjuvant therapy; p = 0.44). Adequate lymphadenectomy was not associated with neoadjuvant therapy (40.5% vs. 40.8%, odds ratio [OR] 0.94, 95% confidence interval [CI] 0.82-1.07), but was associated with surgical approach (52.7% of laparoscopic cases, OR 1.28, 95% CI 1.06-1.56; 61.2% of robotic cases, OR 1.71, 95% CI 1.34-2.19, vs. 43.5% of open cases), and increasing annual esophagectomy volume (55.6% in the fourth quartile vs. 32.6% in the first quartile; OR 3.57, 95% CI 2.35-5.43).

CONCLUSIONS

Despite increases over time, only 50% of patients undergo adequate lymphadenectomy during esophageal cancer resection. Adequate lymphadenectomy was not associated with neoadjuvant therapy. Focusing on surgical approach and esophagectomy volume may further improve adequate lymphadenectomy rates.

Minimally invasive techniques for transthoracic oesophagectomy for oesophageal cancer: systematic review and network meta-analysis

BACKGROUND

Oesophagectomy is a demanding operation that can be performed by different approaches including open surgery or a combination of minimal access techniques. This systematic review and network meta-analysis aimed to evaluate the clinical outcomes of open, minimally invasive and robotic oesophagectomy techniques for oesophageal cancer.

METHODS

A systematic literature search was conducted for studies reporting open oesophagectomy, laparoscopically assisted oesophagectomy (LAO), thoracoscopically assisted oesophagectomy (TAO), totally minimally invasive oesophagectomy (MIO) or robotic MIO (RAMIO) for oesophagectomy. A network meta-analysis of intraoperative (operating time, blood loss), postoperative (overall complications, anastomotic leaks, chyle leak, duration of hospital stay) and oncological (R0 resection, lymphadenectomy) outcomes, and survival was performed.

RESULTS

Ninety-eight studies involving 32 315 patients were included in the network meta-analysis (open 17 824, 55·2 per cent; LAO 1576, 4·9 per cent; TAO 2421 7·5 per cent; MIO 9558, 29·6 per cent; RAMIO 917, 2·8 per cent). Compared with open oesophagectomy, both MIO and RAMIO were associated with less blood loss, significantly lower rates of pulmonary complications, shorter duration of stay and higher lymph node yield. There were no significant differences between surgical techniques in surgical-site infections, chyle leak, and 30- and 90-day mortality. MIO and RAMIO had better 1- and 5-year survival rates respectively compared with open surgery.

CONCLUSION

Minimally invasive and robotic techniques for oesophagectomy are associated with reduced perioperative morbidity and duration of hospital stay, with no compromise of oncological outcomes but no improvement in perioperative mortality.

Recurrent laryngeal nerve monitoring during totally robot-assisted Ivor Lewis esophagectomy

Purpose

The robot-assisted approach for Ivor Lewis esophagectomy offers an enlarged, three-dimensional overview of the intraoperative situs. The vagal nerve (VN) can easily be detected, preserved, and intentionally resected below the separation point of the recurrent laryngeal nerve (RLN). However, postoperative vocal cord paresis can result from vagal or RLN injury during radical lymph node dissection, presenting a challenge to the operating surgeon.

Methods

From May to August 2019, 10 cases of robot-assisted minimally invasive esophagectomy (RAMIE) with extended 2-field lymphadenectomy, performed at the University Medical Center Mainz, were included in a prospective cohort study. Bilateral intermittent intraoperative nerve monitoring (IONM) of the RLN and VN was performed, including pre- and postoperative laryngoscopy assessment.

Results

Reliable mean signals of the right VN (2.57 mV/4.50 ms) and the RLN (left 1.24 mV/3.71 ms, right 0.85 mV/3.56 ms) were obtained. IONM facilitated the identification of the exact height of separation of the right RLN from the VN. There were no cases of permanent postoperative vocal paresis. Median lymph node count from the paratracheal stations was 5 lymph nodes.

Conclusion

IONM was feasible during RAMIE. The intraoperative identification of the RLN location contributed to the accuracy of lymph node dissection of the paratracheal lymph node stations. RLN damage and subsequent postoperative vocal cord paresis can potentially be prevented by IONM.

Recent advances in minimally invasive esophagectomy for squamous esophageal cancer

Over the past decade there has been tremendous development in the clinical application of minimally invasive esophagectomy (MIE) for the treatment of squamous esophageal carcinoma. The major challenges in the performance of MIE include limitations in visualization and manipulation within the confined, rigid thoracic cavity; the need for adequate patient positioning and anesthetic techniques to accommodate the surgical exposure; and changes in the surgical steps for achieving radical nodal dissection, especially for the superior mediastinum. The surgical procedure for MIE is more and more standardized, and there is an increasing practice of MIE worldwide. Randomized trials and meta-analyses have confirmed the advantages of MIE over open esophagectomy, including a significantly lower rate of complications and shorter hospital stays. The recent application of robotics technologies for MIE has further enhanced the quality and safety of the surgical dissection, while intraoperative nerve monitoring has contributed to a lower rate of recurrent laryngeal nerve palsy. With the application of new technologies, we expect further improvement in surgical outcomes for MIE in the treatment of squamous esophageal cancer.

Assessment of Quality Outcomes and Learning Curve for Robot-Assisted Minimally Invasive McKeown Esophagectomy

BACKGROUND

This study aimed to identify the results of the quality assessment and the learning curve of robot-assisted minimally invasive McKeown esophagectomy (RAMIE-MK).

METHODS

The study retrospectively reviewed the data of 400 consecutive patients with esophageal cancer who underwent RAMIE-MK by a single surgeon from November 2015 to March 2019. Cumulative summation analysis of the learning curve was performed. The patients were divided into decile cohorts of 40 cases to minimize demographic deviations and to maximize the power of detecting statistically significant changes in performance.

RESULTS

The 90-day mortality rate for all the patients was 0.5% (2 cases). The authors' experience was divided into the ascending phase (40 cases), the plateau phase (175 cases), and the descending phase (185 cases). After 40 cases, significant improvements in operative time (328 vs. 251 min; P = 0.019), estimated blood loss (350 vs. 200 ml; P = 0.031), and conversion rates (12.5% vs. 2.5%; P < 0.001) were observed. After 80 cases, a decrease in the rates of anastomotic leakage (22.5% vs. 8.1%; P = 0.001) and vocal cord palsy (31.3% vs. 18.4%; P = 0.024) was observed. The number of harvested lymph nodes increased after 40 cases (13 vs. 23; P < 0.001), especially for lymph nodes along the recurrent laryngeal nerve (3.0 vs. 6.0; P < 0.001).

CONCLUSIONS

The learning phase of RAMIE-MK consists of 40 cases, and quality outcomes can be improved after 80 procedures. Several turning points related to the optimization of surgical outcomes can be used as benchmarks for surgeons performing RAMIE-MK.

Past, present, and future of three-field lymphadenectomy for thoracic esophageal cancer

In spite of repeated appeal of the effectiveness of three-field lymphadenectomy (3FL) by Japanese esophageal surgeons, it has not been accepted worldwide as a standard therapeutic measure for thoracic esophageal cancer. In this review, a concise summary of the history of 3FL, its present position, and its future perspective is discussed. Although a lack of randomized controlled trial (RCT) is one of the largest criticisms of 3FL, it seems difficult to make 3FL world-standard even if a RCT with a positive result was made. The essence of 3FL has revealed the fact that bilateral cervical paraesophageal nodes and nodes in the bilateral supraclavicular fossae are regional nodes of thoracic esophageal cancer. To let the world admit this essence should be the real endpoint of "3FL issue" without RCT. In the era of new modalities, Japanese surgeons should be free from the idea that 3FL is indispensable though the essence of 3FL should remain.

Short- and mid-term outcomes of robotic versus thoraco-laparoscopic McKeown esophagectomy for squamous cell esophageal cancer: a propensity score-matched study

Controversy exists on the advantages of robotic McKeown esophagectomy (RME) versus thoraco-laparoscopic McKeown esophagectomy (TLME). The aim was to evaluate the short- and mid-term outcomes of RME and TLME in the treatment of patients with esophageal squamous cell carcinoma (ESCC). A consecutive series of 652 patients, 280 in RME and 372 in TLME, who underwent minimally invasive McKeown esophagectomy for ESCC at our department from November 2015 to June 2018 was analyzed. A propensity score-matched comparison with clinicopathological covariates was performed between the two groups. Complications were categorized based on the Esophagectomy Complications Consensus Group (ECCG) recommendation. To identify the recurrence, all patients with R0 resection were followed with a median follow-up period of 20.2 months (range 1-33 months). After propensity score matching, 271 patients were identified for each cohort. In the matched cohorts, two patients died within 90 days in TLME, whereas no patients died in RME. RME was associated with similar intraoperative blood loss (P = 0.895), but with shorter surgical duration (244.5 vs. 276.0 min, P < 0.001), shorter thoracic duration (85.0 vs. 102.9 min, P < 0.001) and lower thoracic conversions (0.7% vs. 5.9%, P = 0.001). In spite of the similar results on total and thoracic lymph nodes dissection, RME yielded more lymph nodes along recurrent laryngeal nerve (4.8 vs. 4.1, P = 0.012), as well as the higher incidence of recurrent nerve injury (29.2% vs. 15.1%, P < 0.001) when compared to TLME. Tumor recurrence occurred in 30 patients and was locoregional only in 9 (3.5%) patients, systemic only in 17 (6.7%) patients, and combined in 4 (1.6%) patients in RME, while in 26 patients and was locoregional only in 10 (10.6%) patients, systemic only in 7 (2.8%) patients, and combined in 9 (3.6%) patients in TLME. RME was associated with a lower rate of mediastinal lymph nodes recurrence (2.0% vs. 5.3%, P = 0.044). Overall and disease-free survival was not different between the two cohorts (P = 0.097 and P = 0.248, respectively). RME was shown to be a safe and oncologically effective approach with favorable short- and mid-term outcomes in the treatment of patients with ESCC.

Prevention of intra-thoracic recurrent laryngeal nerve injury with robot-assisted esophagectomy

PURPOSE

Transthoracic esophagectomy for esophageal cancer is one of the most invasive procedures in surgery for gastrointestinal cancer. Serious complications sometimes occur after esophageal cancer surgery, including recurrent laryngeal nerve injury and pneumonia. The purpose of this study was to access the possibility of robot-assisted thoracoscopic esophagectomy for esophageal cancer in terms of preventing recurrent laryngeal nerve injury.

METHODS

Operations in thoracic part were performed in prone position with bilateral ventilation. During dissection of the recurrent laryngeal nerve lymph nodes, thin blood vessels were coagulated with Maryland bipolar forceps in the left hand and then dissected with monopolar scissors in the right hand. Especially when dissecting left recurrent laryngeal nerve lymph nodes, the nerve was left unisolated from the vascular sheath that involves the aortic arch. Short-term outcomes including operative time, estimated blood loss, and postoperative complications including recurrent laryngeal nerve injury were accessed.

RESULTS

From November 2018 to January 2020, 20 patients underwent robot-assisted thoracoscopic esophagectomy for esophageal cancer. Thoracic operative time was 242 min, estimated blood loss in the thoracic part was minimal, the number of dissected mediastinal lymph nodes was 19 (all median), and the incidence rates of recurrent laryngeal nerve injury and pneumonia were 10% (2 case) and 10% (2 cases), respectively.

CONCLUSION

Robot-assisted thoracoscopic esophagectomy for esophageal cancer has the possibility of reducing recurrent laryngeal nerve injury even in the introductory period. Randomized controlled trials are required to confirm this advantage of the robotic surgery.

Robot-assisted minimally invasive esophagectomy (RAMIE) compared to conventional minimally invasive esophagectomy (MIE) for esophageal cancer: a propensity-matched analysis

Robot-assisted minimally invasive esophagectomy (RAMIE) is increasingly being applied as treatment for esophageal cancer. In this study, the results of 50 RAMIE procedures were compared with 50 conventional minimally invasive esophagectomy (MIE) operations, which had been the standard treatment for esophageal cancer prior to the robotic era. Between April 2016 and March 2018, data of 100 consecutive patients with esophageal carcinoma undergoing modified Ivor Lewis esophagectomy were prospectively collected. All operations were performed by the same surgeon using an identical intrathoracic anastomotic reconstruction technique with the same perioperative management and pain control regimen. Intra-operative and postoperative complications were graded according to definitions stated by the Esophagectomy Complications Consensus Group. Data analysis was carried out with and without propensity score matching. Baseline characteristics did not show significant differences between the RAMIE and MIE group. Propensity score matching of the initial group of 100 patients resulted in two equal groups of 40 patients for each surgical approach. In the RAMIE group, the median total lymph node yield was 27 (range 13-84) compared to 23 in the MIE group (range 11-48), P = 0.053. Median intensive care unit (ICU) stay was 1 day (range 1-43) in the RAMIE group compared to 2 days (range 1-17) in the MIE group (P = 0.029). The incidence of postoperative complications was not significantly different between the two groups (P = 0.581). In this propensity-matched study comparing RAMIE to MIE, ICU stay was significantly shorter in the RAMIE group. There was a trend in improved lymphadenectomy in RAMIE.

Minimally Invasive Esophagectomy: A Consensus Statement

BACKGROUND

Minimally invasive esophagectomy (MIE) is increasingly performed in various ways. The lack of international definitions and nomenclature makes accurate comparison of outcomes difficult.

METHODS

An international, multispecialty consensus-writing committee constructed definitions and nomenclature for MIE. After a PubMed search, vetting, and review with all authors, a consensus was reached.

RESULTS

The proposed definition for MIE is an operation "that removes part or all of the esophagus, does not retract, lift, spread or remove any part of the chest or abdominal wall and the surgeon's and assistant's vision of the operative field is via a monitor, the patient's tissue is manipulated only by instruments that are controlled by the operating surgeon or team, except for during the neck portion if used." A flexible nomenclature is proposed that attempts to describe current and future operations and systems.

CONCLUSIONS

Definitions and nomenclature for MIE are needed to ensure that future studies accurately compare results and outcomes of similar operations. Nomenclatures allow surgeons, researchers, and patients from different cultures to use a common language to facilitate communication and compare. This process is required in order to improve patient outcomes globally to drive adoption of best of practice, yet is lacking for MIE.